A senior US defence official said on Thursday that while recent military activities by China’s air force over Taiwan were considered an attempt at “intimidation”, the Pentagon would not “take the bait and respond”.

Thomas Harvey III, the acting assistant secretary for strategy, plans and capabilities at the Defence Department, told the South China Morning Post that the mainland’s flights around the island were “a definite message of intimidation”.

Harvey cautioned that “we are mindful of the problems with the [Chinese] challenges and potential escalation”. The Pentagon will not “take the bait and respond to provocations by China trying to initiate anything”, he said.

Harvey advises US Defence Secretary James Mattis on national security and military strategy, including contingency plans needed to respond to perceived aggressions.

The People’s Liberation Army Air Force confirmed on Thursday that it had conducted a second round of training flights in two weeks around Taiwan, adding that it marked a “historical shift” in its combat ability.

A report on the air force’s official microblog said that multiple missions had been launched from separate bases featuring fighter jets, early warning planes and the H-6K long-range bomber.

The planes circled Taiwan, crossing the Bashi Strait to the south and the Miyako Strait to the north along China’s naval border with Japan, according to the report.

Tensions between Beijing and Taiwan have risen in recent months, with China conducting several military drills near Taiwan. Since the 1949 civil war, Beijing has regarded the self-ruled Taiwan as a wayward province, to be brought under mainland China’s rule by force if necessary.

In March, in his closing speech to the National People’s Congress, Chinese President Xi Jinping dismissed any moves toward independence for Taiwan, saying that any attempts at separatism would “face the punishment of history”.

Punctuating that threat, just hours later an aircraft carrier group from the Chinese mainland, led by the mainland’s sole operational aircraft carrier, the Liaoning, began making its way through the narrow Taiwan Strait, though it kept on its western side.

The latest air force runs coincided with a pair of US strategic bombers flying closer to China’s southern coastline on Tuesday afternoon.

Two US B-52 strategic bombers reportedly flew within 250 kilometres of Guangdong province’s coastline, according to Taiwan media and Aircraft Spots, a Twitter group that tracks aircraft movement and the deployment of the US Air Force.

A Pentagon spokesman did not respond to a request for confirmation of the B-52 runs. The two bombers were believed to have come from the US military base on the Pacific island territory of Guam.

However, Harvey said the bombers had been deployed to reassure American allies in the Pacific region that the US would continue to be a presence in Asia. “China has said they want us to leave the region,” he said. “We are not going to leave the region.”

But he also raised the possibility of a miscalculation that would lead to military conflicts between the two nuclear powers.

Harvey said that conflict was “always a possibility when you have military operated in the same space”.